Prognostic Significance of Intraindividual CT and MRI LI-RADS Agreement and Discordance in Hepatocellular Carcinoma.

Purpose To assess the intraindividual concordance and discordance in Liver Imaging Reporting and Data System (LI-RADS) categorizations between CT and MRI for surgically resected hepatocellular carcinoma (HCC) and to evaluate their association with early postsurgical recurrence. Materials and Methods This dual-center retrospective study included patients who underwent both CT and MRI before hepatic resection for HCC between January 2016 and December 2020. For each HCC lesion, the LI-RADS category was independently assigned at CT and MRI. Univariable and multivariable Cox regression analyses were performed to evaluate the associations between the CT and MRI LI-RADS categorizations (LI-RADS category M [LR-M] vs LI-RADS category 4 or 5 [LR-4/5]) and 2-year recurrence-free survival (RFS) rate. Patients were classified into three groups according to the CT or MRI LI-RADS categorization: LR-M at both CT and MRI, at only one modality, or at neither CT or MRI. The 2-year RFS was compared among the groups. Results A total of 319 patients (mean age, 58.8 years ± 9.7 [SD]; 248 male patients) were included, with HCC lesions of 114 (35.7%) patients showing discrepant CT or MRI LI-RADS categorizations. LR-M categorization was more common at MRI than at CT (21.6% vs 6.0%;